U.S. patent number 9,623,942 [Application Number 14/787,195] was granted by the patent office on 2017-04-18 for retractable thruster.
This patent grant is currently assigned to FINCANTIERI S.p.A.. The grantee listed for this patent is FINCANTIERI S.p.A.. Invention is credited to Stefano Bucci, Alessandro Calcagno, Giovanni Magnano, Giacomo Schiaffino.
United States Patent |
9,623,942 |
Schiaffino , et al. |
April 18, 2017 |
Retractable thruster
Abstract
A propulsion assembly of a ship or floating platform includes a
housing within a hull or platform. The housing is watertight except
for an opening external to the hull. A stationary motor is arranged
in the hull external to the housing. A thruster is external to the
hull to generate thrust on the ship or floating platform. A
telescopic driving shaft passes sealingly through a housing wall to
connect the motor and the thruster and to transmit movement from
the motor to the thruster. The thruster retracts within the housing
through the opening. A separate submersible movable hatch is
disconnectable from the thruster and the housing and passes
externally to the hull, and seals the opening to form a watertight
closed chamber. A fluid evacuation device evacuates fluid within
the closed chamber so the thruster, when retracted in the housing
and closed by the hatch, forms the closed chamber.
Inventors: |
Schiaffino; Giacomo (Trieste,
IT), Calcagno; Alessandro (Trieste, IT),
Bucci; Stefano (Trieste, IT), Magnano; Giovanni
(Trieste, IT) |
Applicant: |
Name |
City |
State |
Country |
Type |
FINCANTIERI S.p.A. |
Trieste |
N/A |
IT |
|
|
Assignee: |
FINCANTIERI S.p.A. (Trieste,
IT)
|
Family
ID: |
48793398 |
Appl.
No.: |
14/787,195 |
Filed: |
March 19, 2014 |
PCT
Filed: |
March 19, 2014 |
PCT No.: |
PCT/IB2014/059971 |
371(c)(1),(2),(4) Date: |
October 26, 2015 |
PCT
Pub. No.: |
WO2014/174385 |
PCT
Pub. Date: |
October 30, 2014 |
Prior Publication Data
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|
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Document
Identifier |
Publication Date |
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US 20160101839 A1 |
Apr 14, 2016 |
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Foreign Application Priority Data
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|
|
|
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Apr 26, 2013 [IT] |
|
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MI2013A0694 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B63H
5/14 (20130101); B63H 5/1252 (20130101); B63B
17/0018 (20130101); B63H 5/125 (20130101); B63H
21/36 (20130101); B63H 2005/1256 (20130101); B63H
2025/425 (20130101) |
Current International
Class: |
B63H
5/125 (20060101); B63H 21/36 (20060101); B63B
17/00 (20060101); B63H 5/14 (20060101); B63H
25/42 (20060101) |
Field of
Search: |
;440/53,61R,61S,63,66,67,68,69,71,76,79 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 591 969 |
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Apr 1994 |
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EP |
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2012-0017025 |
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Feb 2012 |
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KR |
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WO 2010/136012 |
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Dec 2010 |
|
WO |
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Other References
International Search Report for corresponding International Patent
Application No. PCT/IB2014/059971 mailed Jul. 10, 2014. cited by
applicant.
|
Primary Examiner: Venne; Daniel V
Attorney, Agent or Firm: Merchant & Gould P.C.
Claims
The invention claimed is:
1. A ship or floating platform propulsion assembly, comprising a
hull insert, or trunk, forming a housing, or propeller case,
located within a hull of a ship or platform; said housing being
watertight with respect to the hull in all walls thereof, except
for an opening externally to the hull of the ship or platform; a
motor; said motor being arranged in said hull, but externally to
said housing, and being arranged stationary with respect to said
hull; a thruster arranged externally to said hull to generate a
propulsion thrust on said ship or floating platform; a telescopic
driving shaft passing through and forming a seal with one of the
walls of said housing to operatively connect said motor and said
thruster and to transmit movement from the motor to the thruster
for the movement of said thruster; said thruster being retractable
within said housing passing through said opening; a submersible
movable hatch in a separate piece and completely disconnectable
from said thruster and said housing; said movable hatch passing
externally to said hull, and sealing and closing said opening of
said housing, closing said housing and forming a watertight closed
chamber; a fluid evacuation device for evacuating fluid, which is
present within said closed chamber, so as to arrange said thruster,
when retracted in said housing closed by said hatch to form said
closed chamber, at least partially in air.
2. The assembly according to claim 1, wherein said housing, in
operative conditions, is arranged at least with a part thereof
under a free surface of the fluid, for example, sea water, on which
said hull is floating; wherein said walls of said housing are walls
integrated in the hull, avoiding the use of a hull seat into which
said housing is to be inserted; wherein said telescopic driving
shaft is passing and watertight through one of the walls of said
housing to operatively connect said motor and, in a selectively
detachable manner, said thruster and to transmit the movement from
the motor to the thruster for the movement of said thruster;
wherein said thruster is retractable within said housing passing
through said opening so as not to project externally to said hull,
when said thruster is in a completely retracted position thereof;
wherein a fluid evacuation device for evacuating fluid present
within said closed chamber comprises a ballast/bilge pump connected
with said chamber for evacuating fluid present in said chamber even
when the hull or platform is submersed, when said chamber is closed
by said submersible movable hatch, so as to arrange said thruster,
when retracted in said housing and closed by said hatch to form
said closed chamber, at least partially in air.
3. The assembly according to claim 1, wherein said telescopic
driving shaft comprises a shaft axis, for example, arranged
vertical substantially transversely to the free water surface; and
wherein said shaft comprises an azimuthal driving shaft and a
telescopic power driving shaft; wherein said thruster has a
thruster axis, or thrust actuating axis, which is adjustable in
inclination with respect to said telescopic shaft axis by a
predetermined angle so as to orient thrust of the thruster with
respect to the hull or other obstacles present under the hull.
4. The assembly according to claim 1, wherein said fluid evacuation
device is suitable to reintroduction of fluid into the closed
chamber, for example, at the end of the maintenance operations;
wherein said assembly further comprises an air pumping device for
introducing air into the closed chamber, for example, tubes for the
connection of the closed chamber, or propeller case, with the
inside of the hull.
5. The assembly according to claim 1, wherein a maintenance access
hatch is configured for watertight opening and closing a portion of
the wall of the housing for accessing the closed chamber by
maintenance personnel.
6. The assembly according to claim 1, wherein further comprising
suspension chains and/or cables, or hanging cables configured for
being connected to said submersible movable hatch for the handling
thereof outside the hull and the coupling thereof to said opening;
wherein said assembly further comprises passages provided in at
least one of the walls of said housing to insert the hanging cables
or chains in said housing to hang the submersible movable hatch
passing through said housing or to hang said thruster when said
thruster is disconnected from said telescopic driving shaft;
wherein said assembly further comprises pulleys, as the only means
for handling both the hanging cables of said submersible movable
hatch and the hanging cables of said thruster.
7. The assembly according to claim 1, wherein a guide cross is
provided in said housing, to guide said telescopic driving shaft in
at least a length thereof located within said housing and to
discharge onto the hull thrust actions of the thruster.
8. The assembly according to claim 1, further comprising a
telescopic driving shaft and thruster connection joint which is
suitable to removably connect the thruster to the telescopic
driving shaft; and wherein a first watertight protection or
covering closure cuff is provided, which is removably connectable
to a shaft free end, or first joint flange, and a second watertight
protection or covering closure cuff removably connectable to a
portion for connection to the thruster shaft, or second joint
flange to completely separate said thruster from said shaft and to
submerse said thruster by withdrawing said thruster from said
housing in a fluid.
9. The assembly according to claim 1, wherein said motor is an
electric motor; wherein said assembly further comprises a thruster
lifting device connected to a support device for handling a movable
portion of the telescopic driving shaft and of the thruster to
extend the telescopic driving shaft outside said housing or to
retract said thruster into said housing; further comprising guide
candles for guiding the movement of said support device.
10. The assembly according to claim 1, wherein said hull insert, or
trunk, is a structure integrated in the hull.
Description
This application is a National Stage Application of
PCT/IB2014/059971, filed 19 Mar. 2014 which claims benefit of
Serial No. MI2013A000694, filed 26 Apr. 2013 in Italy, and which
applications are incorporated herein by reference. To the extent
appropriate, a claim of priority is made to each of the above
disclosed applications.
FIELD OF THE INVENTION
The present invention relates to a retractable thruster assembly of
a ship or a floating platform.
Particularly, the present invention relates to a retractable
thruster assembly suitable to be maintained while the ship or the
floating platform is at anchor, as well as in the case of a ship or
platform that is floating.
BACKGROUND OF THE ART
Retractable thrusters or azimuthal retractable thrusters have been
long known. The azimuthal thrusters are marine thrusters rotatable
about a vertical axis (hence the name of azimuthal), thereby
allowing the orientation of the propeller in any horizontal
directions, making the presence of a rudder redundant. These
azimuthal thrusters allow a considerable maneuverability of ships,
but also of floating platforms, which require to accurately
maintain a position when out at sea.
Such solutions are known, for example, from U.S. Pat. No.
6,375,524, U.S. Pat. No. 6,439,936, US 2001/029133, EP 0 591 969,
KR 2012/0017025, U.S. Pat. No. 6,375,524, WO 2010/136012.
Retractable thrusters are also known from the state of the art,
which are retracted into housings that are suitable to the
maintenance thereof.
For example, from the document U.S. Pat. No. 5,397,255 by Schottel
Werft Joseph Becker GmbH. & Co., KG, a propulsion unit for a
ship is known, having a thruster with a propeller that may be
retracted into a cylindrical case and closed by a cover plate that
is secured to the thruster, so that water present in the
cylindrical case may be pumped out, once it is closed, with the
purpose of ensuring the access for the thruster inspection and
maintenance.
Particularly, this known solution provides for a propeller
projecting under the bottom of the ship and retractable in a case
arranged within the bottom, which is locally flat. Said case is
surrounded at the lower edge thereof by an annular groove
comprising a gasket to seal said case when the cover plate firmly
at the thruster is retracted and contacts the bottom. Said plate is
firmly secured in a removable manner to the thruster so that the
propeller and the plate may be lifted and lowered vertically
together.
This known solution, while allowing the maintenance of the thruster
when it is retracted within of the hull, is particularly bulky and
heavy in all the steps of use thereof. Particularly, the closing
plate that is firmly secured to the thruster adds additional
weight, as well as a drag of the ship for the entire time of normal
use of the thruster in the extended position.
Of course, the presence of this closing plate secured to the
thruster makes this solution unsuitable for thrusters inclinable
with respect to the vertical axis, such as, for example the
solutions described in the documents U.S. Pat. No. 7,641,526 and
U.S. Pat. No. 4,580,517.
Furthermore, it has to be considered that these known retractable
thrusters, moreover in the case of applications on floating
platforms, remain in the extended and operative position most of
the time of use of the platform or ship. Therefore, the overall
dimensions given by the closing plate and the ship drag thereof are
a particularly felt problem.
Furthermore, in these applications, the substantially constant
exposure of the closing plate to the substances that are present
externally to the hull lead to a degradation of the plate portions
that are suitable to the coupling with the hull, sometimes
compromising the perfect coupling thereof to the hull. For example,
suppose how the effect of building-up incrustations may make the
closure of the plate in contact with the bottom problematic and the
risks following any water leakage into the cylindrical case into
which the thruster is retracted for the maintenance thereof.
Furthermore, this known solution of retractable thruster forces to
the assembling of the thruster itself and the motor associated
thereto on a scaffolding that allows a vertical movement suitable
to the withdrawal and the retraction of the thruster into the hull.
Therefore, this solution has necessarily to provide for the use of
a, bulky interspace arranged vertically in the hull, which allows,
in any time during the navigation, retracting the support
scaffolding of the thruster motor within the hull itself, resulting
in a considerable waste of volume within the hull, which volume the
ship owner would like to be intended for other paying uses.
This solution necessarily forces to a specific designing of the
retractable thruster provided with the special closing plate
thereof. Supposing a ship or a floating platform of medium or large
dimensions, it is realized that, in order properly maneuver, a
plurality of retractable thrusters will be present, each being
provided with the closing plate thereof and the scaffolding thereof
for handling the thruster into the cylindrical case. The presence
of this plurality of retractable thrusters, implemented according
this known solution, is not only particularly heavy, but moreover
bulky and arranged in different areas of the hull, thus forcing to
implement several vertical interspaces, which may sometimes reach
the entire height of the same hull, segmenting the internal volume
of the ship, thus making the use thereof still more complex.
Other solutions are known, for example, from U.S. Pat. No.
2,987,027, U.S. Pat. No. 3,483,843, U.S. Pat. No. 2,885,990, U.S.
Pat. No. 3,030,910. However, no one of these documents proposes a
solution to the above-mentioned drawbacks and needs. Particularly,
none of these solutions proposes a retractable thruster assembly
that is as light-weighted as possible, not very bulky, and avoids
any ship drag as much as possible, while ensuring at least the
routine maintenance of the thruster when it is retracted within the
hull.
Therefore, a particularly felt problem is to propose a thruster
assembly for a ship or a floating platform, that allows the
maintenance of the thruster itself when the ship or platform is
floating, minimizing the weight and the overall dimensions of the
structures interlocked to the retractable thruster.
SUMMARY OF THE INVENTION
Therefore, the object of the present invention is to devise and
propose a retractable thruster assembly that allows solving the
above-mentioned drawbacks.
A solution to these and other problems is given by a thruster
assembly of a ship or a floating platform.
In accordance with a general embodiment of the present invention, a
propulsion assembly of a ship, or a floating platform, comprises a
hull insert forming a housing, or propeller case, arranged within a
hull of said ship or platform. In particular, this housing is a
watertight housing, at least with respect to the hull, in all the
walls thereof, except for an opening that opens externally to the
hull of the ship or platform.
A motor is provided for within the hull, for example, but not
necessarily, an electric motor, which is arranged externally to
said housing and secured in a stationary manner to the hull, or, in
other terms, arranged connected with the hull so as to remain in a
stationary position thereto.
Said assembly further comprises a thruster, for example, but not
necessarily, a propeller foot. This thruster is a thruster that is
extractable and retractable within the hull, and it is suitable to
be arranged externally to said hull to generate a propulsion thrust
on said ship or platform.
Advantageously, said assembly further comprises a telescopic
driving shaft. Said telescopic driving shaft is arranged passing
through and forming a seal with one of the walls of said housing to
operatively connect said motor secured to the hull and, for
example, but not necessarily, in an detachable manner, said
thruster.
Advantageously, said thruster is retractable within said housing,
passing through said opening so as not to project externally to the
hull when it is in the retracted position.
With further advantage, said assembly provides for a submersible
movablemovable hatch made in a separate piece and completely
disconnected from said thruster and said housing.
Said submersible movable hatch is suitable to associate externally
to said housing, passing externally to said hull, for sealing and
closing said opening of said housing, closing the housing to form a
watertight closed chamber with respect to the outside of the
hull.
Said assembly further provides for a fluid evacuation device for
evacuating a fluid, for example, but not necessarily, sea water,
which is present within said closed chamber, so as to arrange said
thruster at least partially in air, when completely retracted in
said housing and closed by said submersible movable hatch in a
closed chamber.
By virtue of the provision of a watertight closed chamber, the
present solution allows carrying out the maintenance of the
propeller foot when the ship or platform is floating. By virtue of
the possibility of evacuating the fluid, for example, sea water, it
will be possible to carry out minor maintenance operations, for
example, replacing the seals of the propeller foot, when the latter
is arranged within the hull in said housing when the ship or
platform is floating, maybe far from the shore or another dock.
The provision of a submersible movable hatch that is completely
detachable from the thruster allows minimizing the assembly weight,
hence of the structures interlocked to the retractable thruster,
and it allows implementing a hull closing system to create an area,
a watertight closed chamber, which is suitable to the maintenance
and inspection of the thruster, which solution at the same time
allows not to affect the thruster performance when this is extended
to the exterior of the hull.
By virtue of the provision of a telescopic driving shaft, it is
possible to implement a not very bulky assembly, which leaves the
motor in a stationary position with respect to the hull, avoiding
taking a considerable volume within the hull itself, which volume
may be dedicated to other uses. Furthermore, by virtue of this
solution, it is possible to avoid providing scaffoldings for the
movement of motor components, considerably simplifying the
construction of the assembly and reducing the overall dimensions
while facilitating maintenance.
By virtue of the proposed solution, it is possible to increase
safety during the maintenance steps, avoiding the build-up of dirt
or incrustations in bulkheads or hatches suitable for a watertight
closure, and in particular avoiding undesired infiltrations.
Advantageously, the provision of a submersible movable hatch in a
separate piece and completely disconnected from the thruster and
the housing allows, by virtue of scheduled maintenance operations,
arranging only one closing hatch for multiple housings, so as to
proceed with the maintenance of multiple retractable thrusters that
are present on the same ship or platform through only one
hatch.
Furthermore, the proposed solution is particularly advantageous,
since it allows using the same handling means of the submersible
movable hatch, also optionally to couple, hang and optionally lower
the thruster, further increasing the constructive simplicity of the
assembly, hence the safety of use.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the assembly according to
the invention will be apparent from the description set forth below
of preferred embodiment examples thereof, given by way of
illustrative, non-limiting example, with reference to the appended
figures, in which:
FIG. 1 shows an axonometric and partially sectioned view, so as to
show the contents thereof, a retractable thruster assembly for
ships or floating platforms;
FIG. 2 illustrates a side, partially sectioned view, the assembly
of FIG. 1;
FIG. 3A shows in a front, partially sectioned view, the assembly of
FIG. 1;
FIG. 3B shows a front, partially sectioned view, the assembly of
FIG. 1, but with the thruster in the extendedextended position and
the telescopic driving shaft in an elongated position;
FIGS. 4A and 4B represent a bottom view and a sectioned view,
respectively, of the section immediately above of the thruster as
seen towards the thruster of the assembly of FIG. 1;
FIG. 5 shows the side, partially sectioned view of a retractable
thruster assembly in a first maintenance step, in which it is
lowered to the sea laterally to the hull when the submersible
movable hatch closes the housing for the thruster;
FIG. 6 shows the side, partially sectioned view of the retractable
thruster assembly of FIG. 5 in a second maintenance step, in which
the submersible movable hatch is brought near to the housing
opening;
FIG. 7 shows the side, partially sectioned view of the retractable
thruster assembly of FIG. 5 in a third maintenance step, in which
the submersible movable hatch is hung from hanging cables passing
through the housing;
FIG. 8 shows the side, partially sectioned view of the retractable
thruster assembly of FIG. 5 in a fourth maintenance step, in which
the submersible movable hatch is coupled to the opening;
FIG. 9 shows a sectioned view a detail of the coupling between the
submersible movable hatch and a coupling edge of the hull insert
defining the opening;
FIG. 10 shows the side, partially sectioned view of the retractable
thruster assembly of FIG. 5 in a fifth maintenance step, in which
the closed chamber that is formed by coupling the submersible
movable hatch to the housing opening is at least partially emptied
of water by putting in air at least the part of the thruster that
is ready for the maintenance in situ or for other maintenance
operations;
FIG. 11 shows the side, partially sectioned view of the retractable
thruster assembly of FIG. 5 in a sixth maintenance step, in which
the thruster is supported hanging from hanging cables passing
through a housing wall;
FIG. 12 shows the side, partially sectioned view of the retractable
thruster assembly of FIG. 5 in a seventh maintenance step, in which
the thruster supported hanging from hanging cables is uncoupled
from the telescopic driving shaft and sealing cuffs are fitted on
the free coupling end between shaft and thruster;
FIG. 13 shows the side, partially sectioned view of the retractable
thruster assembly of FIG. 5 in an eighth maintenance step, in which
the closed chamber is filled with water again, the submersible
movable hatch is uncoupled from the edge of the opening, which is
open, and the thruster supported hanging from hanging cables is
gradually lowered outside the hull;
FIG. 14 shows the side, partially sectioned view of the retractable
thruster assembly of FIG. 5 in a ninth maintenance step, in which
the thruster supported hanging from hanging cables is supported by
chains that are external to the hull and gradually lifted high
outside the hull.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
With reference to the above-mentioned Figures, a propulsion
assembly of a ship or floating platform 1 comprises a hull insert
2, also referred to as a trunk, forming a housing 3, also referred
to as a propeller case, located within a hull 4 of a ship or
platform.
In accordance with an embodiment, said housing 3 is a housing
watertight with respect to the hull in all the walls 5 thereof,
except for an opening 6 opening externally to the hull 4 of the
ship or platform.
Advantageously, said assembly further comprises a motor 7 and a
thruster 8, for example a propeller foot.
In accordance with an embodiment, said thruster 8 is suitable to be
arranged externally to said hull 4 to generate a propulsion thrust
on said ship or floating platform. Said thruster 8 is further
retractable within said housing 3 passing through said opening
6.
In accordance with an embodiment, said motor 7 is arranged in said
hull 4, but externally to said housing 3, and it is arranged
stationary with respect to said hull 4, i.e., so as not to move
with respect to the hull even during the withdrawal or retraction
movement of said thruster into said housing 3.
In accordance with an embodiment, said assembly 1 further comprises
a telescopic driving shaft 9. Advantageously, said telescopic
driving shaft 9 is arranged passing through and forming a seal with
one of the walls 5 of said housing 3 to operatively connect said
motor 7 and said thruster 8 and to transmit the movement from the
motor to the thruster for the movement of said thruster 8.
In accordance with an embodiment, said assembly further comprises a
submersible movable hatch 10, made in a separate piece and
completely disconnectable from said thruster 8 and said housing
3.
In accordance with an embodiment, said hatch movable 10 is suitable
to associate externally to said housing 3, passing externally to
said hull 4.
In accordance with an embodiment, said movable hatch 10 is suitable
to seal and close said opening 6 of said housing 3, forming a
watertight closed chamber 11 with respect to the outside of said
hull 4.
In accordance with an embodiment, said assembly further comprises a
fluid evacuation device 12 for evacuating fluid 13, for example,
sea water, which is present within said closed chamber 11 so as to
arrange said thruster 8 at least partially in air, when retracted
in said housing 3 that is closed by said hatch to form said closed
chamber.
In accordance with an embodiment, said housing 3, under operative
conditions of the ship or platform, is arranged at least with a
part thereof under the free surface W-W of the fluid 13, for
example, sea water, on which said hull 4 is floating.
In accordance with an embodiment, said walls 5 of said housing 3
are walls that are integrated in the hull 4, and they avoid the
need to implement a hull seat, for example, an interspace, in which
said housing 3 and all the structures interlocked to the movement
of the thruster are to be inserted.
In accordance with an embodiment, said telescopic driving shaft 9
is received and forms a seal with a portion thereof in one of the
walls 5 of said housing 3 to operatively connect said motor 7 and
said thruster 8 in a selectively detachable manner, in order to
transmit the movement from the motor to the thruster for the
movement of said thruster 8 and to allow, in the case of a
maintenance, separating the thruster from the motor.
In accordance with an embodiment, said thruster 8 is retractable
within said housing 3 passing through said opening 6 so as not to
project externally to said hull 4, when it is in a completely
retracted position thereof.
In accordance with an embodiment, the fluid evacuation device 12
for evacuating fluid 13 present within said closed chamber 11 is
for example at least a ballast/bilge pump connected with said
chamber 11.
In accordance with an embodiment, said telescopic driving shaft 9
comprises a shaft axis V-V, for example, arranged vertical, in
other terms, substantially transversal to the free water surface
W-W. In accordance with an embodiment, said shaft 9 comprises an
azimuthal driving shaft 14 and a telescopic power driving shaft
15.
In accordance with an embodiment, said thruster has a thruster
axis, or thrust actuating axis P-P, which is adjustable in
inclination with respect to said telescopic shaft axis V-V by a
predetermined angle A, so as to orient the thrust of the thruster
with respect to the hull 4 or other obstacles that are present
under the hull.
In accordance with an embodiment, said fluid evacuation device 12
is suitable to the re-imission of fluid into the closed chamber 11,
for example, at the end of the maintenance operations.
In accordance with an embodiment, said assembly further comprises
an air inputting device 16 for inputting air into the closed
chamber 11 when it is emptied of the fluid and to allow a
recirculation of air when maintenance personnel is present therein.
For example, the air inputting device 16 comprises tubes for the
connection of the closed chamber, or propeller case, with the
inside of the hull.
In accordance with an embodiment, said assembly further comprises a
maintenance access hatch 17 for the watertight opening and closure,
of a portion of a wall of said housing 3, allowing accessing the
closed chamber 11 by maintenance personnel of the thruster 8.
In accordance with an embodiment, said assembly further comprises
suspension chains and/or cables, or hanging cables 18, connectable
to said submersible movable hatch 10 for the handling thereof
externally to the hull and the coupling thereof to said opening
6.
In accordance with an embodiment, said assembly further comprises
passages 31 provided for in at least one of the walls 5, for
example, the upper roof, or sky 32, of said housing 3, to insert
hanging cables or chains 18, 20 into said housing to hang said
submersible movable hatch 10 passing through said housing 3 or to
hang said thruster 8 when it is to be disconnected or it is
disconnected from said telescopic driving shaft 9.
In accordance with an embodiment, said assembly further comprises
pulleys 33, as the only means for handling the hanging cables 18 of
said submersible movable hatch 10, as well as for handling the
hanging cables 20 of said thruster 8.
In accordance with an embodiment, a guide cross is provided for in
said housing 3, to guide said telescopic driving shaft 9 in at
least one, or also in at least one length thereof located within
said housing 3 and discharging the thrust actions of the thruster 8
onto the hull 4.
In accordance with an embodiment, said assembly further comprises a
telescopic driving shaft and thruster connection joint 22 suitable
to removably connect the thruster 8 to the telescopic driving shaft
9 to completely separate said thruster from said shaft and immerse
said thruster 8 by withdrawing it from said housing 3 into a fluid,
for example, sea water, to leave said hull 4 in a floating
condition.
In accordance with an embodiment, said assembly further comprises a
first watertight protection, or covering closing cuff 23 that is
removably connectable to the shaft free end 9, or first joint
flange 24.
In accordance with an embodiment, said assembly further comprises a
second watertight protection, or covering closing cuff 25 removably
connectable to the portion for the connection of the thruster 8 to
the shaft, or second joint flange 26.
In accordance with an embodiment, said motor 7 is an electric
motor.
In accordance with an embodiment, said assembly further comprises a
thruster lifting device 27, for example of the oleo-dynamic type,
connected to a support device or support 28 for the handling of a
movable portion of the telescopic driving shaft 9 and of the
thruster 8 to extend it outside said housing 3, or to retract said
thruster 8 into said housing 3.
In accordance with an embodiment, said assembly further comprises
guide candles 19 for guiding the movement of said support 28.
In accordance with an embodiment, said hull insert, or trunk 2, is
a structure integrated into the structure of the hull 4 that does
not need, to define said watertight walls, a separate cell added to
an interspace obtained in the hull.
A method for the maintenance of a propulsion assembly of a ship or
platform 1 during the floating thereof is described herein
below.
Said method, according to a general embodiment method thereof,
comprising the steps of:
providing for a hull insert or trunk 2 forming a housing 3, or
propeller case, located within a hull 4 of a ship;
providing for said housing 3 to be watertight with respect to the
hull 4 in all the walls 5 thereof, except for an opening 6 opening
externally to the hull 4 of the ship;
arranging a motor 7 in said hull externally to said housing 3,
avoiding the change of the position thereof with respect to the
hull 4;
providing for a thruster 8, for example, a propeller foot, which is
suitable to be arranged externally to said hull 4 to generate a
propulsion thrust on said ship or floating platform;
providing for a telescopic driving shaft 9 passing through and
forming a seal with one of the walls 5 of said housing, operatively
connecting said motor 7 and, in a preferably but not necessarily
removable manner, said thruster 8, to transmit the movement from
the motor to the thruster for the movement of said thruster.
Said method provides for the further steps of:
retracting said thruster 8 within said housing 3 passing through
said opening 6, preferably, but not necessarily, preventing it from
projecting externally to said hull;
lowering a submersible movable hatch 10 externally to the hull in a
separate piece and completely disconnected from said thruster 8 and
said housing 3;
associating said submersible movable hatch 10 externally to said
housing 3 and
sealing and closing said opening 6 of said housing, closing said
housing and forming a watertight closed chamber 11 with respect to
the outside of said hull containing said thruster;
evacuating any fluids, for example, sea water 13, which are present
within said housing even when the hull or platform is floating and
partially submersed, when it is closed by said submersible movable
hatch 19, so as to arrange said thruster 8 at least partially in
air.
In accordance with a possible further method, the following steps
are optionally further provided for, of
accessing through a maintenance access hatch 17 said chamber 11 in
said housing 3 for the maintenance of the thruster 8.
In accordance with a possible further method, said maintenance step
comprises the step of replacing propeller seals 29.
In accordance with a possible further method, said maintenance step
comprises the steps of:
disassembling seals protection rings 30
replacing worn propeller seals 29 with new propeller seals 29
evacuating personnel from said chamber 11 of said housing 3 making
it to be lifted through said maintenance access hatch 17 to the
upper decks
sealing closing said housing access hatch 17
flooding said chamber 11
removing the submersible movable hatch 10 from externally to the
hull
bringing said submersible movable hatch 10 back to the surface by
passing externally to the ship.
In accordance with a possible further method, said housing 3 under
operative conditions is arranged at least partially under the free
water surface W-W.
In accordance with a possible further method, said maintenance step
further comprises the step of:
Disassembling, when the ship or platform is floating, of the entire
thruster or propeller foot 8 and withdrawing it from the hull to
bring it back to the surface by passing externally to the floating
ship or platform.
In accordance with a possible further method, said maintenance step
comprises the steps of:
installing the submersible movable hatch 10 in the proximity of the
opening 6 of the housing 3 of the hull insert, or trunk 2, by
hanging cables 18, and by means of the optional aid of diving
personnel
pumping for evacuating the residual water from the chamber, or
propeller case 11, by a fluid evacuation device, for example, but
not necessarily, ballast/bilge pumps of the ship 12
when the case 11 is emptied, allowing personnel access said
case,
lifting the propeller foot 8 with the aid of said hanging
cables
uncoupling the joint 22 by disconnecting the first flange 24 and
the second flange 26 of the joint for the connection of the
telescopic driving shaft 9 to the thruster, or propeller foot 8
lowering the entire propeller foot 8 to allow securing protection
cuffs 23, 25 at the free ends of the shafts and the thruster;
evacuating personnel from the propeller case 11, and
sealing and closing said housing access hatch 17
flooding said chamber 11
removing the submersible movable hatch 10 from externally to the
hull
bringing said submersible movable hatch 10 and said propeller foot
8 back to the surface by passing externally to the hull.
In accordance with a possible further method, said maintenance step
comprises the steps of:
hanging said submersible movable hatch externally to the hull by
suspension chains and cables or hanging cables 18.
In accordance with a possible further method, said maintenance step
comprises the steps of:
hanging said thruster or propeller foot 8 by hanging cables or
chains 20 passing through said housing 3.
In accordance with a possible further method, said maintenance step
comprises the steps of:
inserting into said housing, through closable passages 31 provided
for through the walls 5 of said housing 3, hanging cables or chains
18, 2.0 to hang said submersible movable hatch 10 passing through
said housing or to hang said thruster 8 also disconnecting it from
said telescopic driving shaft 9.
In accordance with a possible further method, said maintenance step
comprises the steps of:
inclining by a predetermined angle A the thruster axis, or thrust
actuating axis P-P, with respect to the telescopic shaft axis V-V
so as to orient the thrust of the thruster with respect to the hull
4 or other obstacles.
In accordance with a possible further method, said maintenance step
comprises the steps of:
guiding said telescopic driving shaft 9 in at least a length
thereof located within said housing by a guide cross 21.
In accordance with a possible further method, said maintenance step
comprises the steps of:
discharging onto the hull the thrust actions of the thruster by
said guide cross 21.
In accordance with a possible further method, said maintenance step
comprises the steps of:
Installing the submersible movable hatch 10 in the proximity of the
opening 6 of the housing 3 of the hull insert or trunk 2 by hanging
cables 18, and optionally by the aid of diving personnel.
In accordance with a possible further method, said maintenance step
comprises the steps of:
bringing said submersible movable hatch 10 and said propeller foot
8 back to the surface by passing externally to the ship.
It shall be apparent that those skilled in the art, with the aim of
meeting contingent, specific needs, will be able to make a number
of modifications and variations to the assembly according to the
invention, all of which anyhow falling within the protection scope
of the invention, as defined by the following claims.
REFERENCES
1 propulsion assembly 2 hull insert 3 housing or propeller case 4
ship hull 5 housing walls 6 housing opening 7 motor 8 thruster 9
telescopic driving shaft 10 submersible movable hatch 11 closed
chamber within housing 12 fluid evacuation device from the chamber
13 fluid--sea water 14 azimuthal driving shaft 15 power driving
shaft 16 air inputting device 17 maintenance access hatch 18 chains
or hanging cables for submersible movable hatch 19 guide candles 20
suspension chains or hanging cables of thruster 21 guide cross 22
thruster shaft connection joint 23 first watertight protection or
covering closure cuff 24 first shaft side joint flange 25 second
watertight protection or covering closure cuff 26 second thruster
side joint flange 27 thruster lifting device 28 support device
handling shaft and propeller foot 29 propeller seals 30 propeller
seals protection 31 passages for chains or cables in housing walls
32 housing or chamber upper roof, sky 33 pulleys for handling
hanging cables 34 edge of hull insert defining the opening for the
coupling to the hatch V-V shaft axis P-P thrust actuating axis, for
example, thruster axis or propeller axis W-W free water surface A
angle between V-V and P-P
* * * * *